Internal-combustion-engine fuel-injection device



Jan. 4 1927.

W. P. WIDDOWSON INTERNAL COMBUSTION ENGINE FUEL INJECTION DEVICE FiledAugust 8, 192.

Patented Jan. 4, 1927.

UNITED STATES WALTER PERCY WIDDOWSO'N, OF LONDON, ENGLAND.

INTEBlNAL CloMBUsTloN-ENGINE FUEL-INJECTION DEVICE.

Application filed August 8, 1921, Serial No.

490,639, and in Great Britain May 5, 1920,

(GRANTED UNDER THE PROVISIONS OF THE ACT OF MARCH '3, 1921, 41- STAT. L,1313.)

This invention relates to internal combustion engines of the typein-which liquid fuel is injected into the combustion chamber,

at or near the end of the compression stroke by means of a. fuelinjection pump, and in which a fuel injection pump pumps the liquidfuelto a fuel injection valve. which is opened by the pressure of theliquid fuel,

or other suitable means, the amount of liquid fuel injected into thecombustion chamber being regulated by a release or spill valve which isopened by control or governing mechanism at a variable or fixed point inthe stroke of the fuel pump plunger, thereby spilling the fuel for theremainder of the stroke of the plunger.

Heretofore it has been proposed in a forced liquid fuel supplv tointernal combustion engines, to provide two by-pass valves designed tobe operated at different periods of the forcing stroke of the oil pump,the two valves being in some cases substituted bya single duplex valve.

' The present invention comprises an internal combustion engine liquidfuel injection device having a spring-loaded injection valve and asingle-spill valve or by-pass in a passage communicating with the fuelreservolr. wherein the bv-pass is not brought into use until aftersufficient fuel has been forced through the injection valve. and a'continuous pressure circuit established between the-pump and the spillvalve.

The release or spill valve may be placed on the body of the fuelinjection valve. or in any other convenient position. and is placed incommunication with the fuel injection valve pump through the injectionvalve. Bv having the spill valve arranged to let the oil furnished bythe remainder of the piston stroke to pass through the injection valvechamber, this chamberis continuously washed out and also slightly cooledThe system may be provided with a liquid fuel strainer arranged betweenthe fuel pump and the injection valve.

. An embodiment of the invention is illustrated by the accompanyingdrawing wherein a is the combustion chamber of an internal combustionengine. I) the fuel injection valve, 1 the body thereof, 0 the spillvalve, d the liquid fuel plunger, and 18 the cam. 1

The fuel injection valve body 1 is screwed into an opening in the enginecasting leading to the combustion chamber, and is provided with an inletpassage 2, and an outlet passage 3, leading respectively to and from apressure chamber 4 wherein fluid pressure of the liq'uid fuel is exertedupon a shoulder 5 on the spindle of the valve 7). This spindle isloadedby a spring 6 in the known manner so thatthe valve 7) will not beraised from its seat until the pressure in the delivered liquid fuelrises above the amount necessary to overcome load of the spring 6.

The inlet passage 2, of the valve casing is connected by a delivery pipe7 to the delivery valve 8 of the liquid fuel pump. and the outletpassage 3 is connected bv a return pipe 9 to the upper side of a spillvalve 0. This spill valve is held on its seat in the valve body 12 by aspring 10, and has a spindle extending through a stuffing box 11. Thisvalve spindle is arranged in line or coaxial with a valve operating rod13 pivoted to a lever 14 secured to a shaft 15 onwhich is secured thepump operating rocking lever 16. One end of this lever is provided witha roller 17, adapted to bear on a cam 18 secured on the cam shaft 19 ofthe engine; the other end of the lever 16 bears in a slot in the pumpplunger (1 in such a manner that when the roller 17 is raised by the cam18, the other end of the lever 16 will force the plunger d into itsbarrel against the action of a return spring 20. Strainer 26 is setunder plunger d to act on the oil before it passes to valve 8.

The underside of nected by a pipe 21 to the underside of the suctionvalve 22 of the fuel pump. The piston 26 supporting the spring 10 on thespindle of the valve 0 is perforated at 27 to admit fluid under pressureto both sides of the piston. The suction valve 22 is placed incommunication with the liquid fuel reservoir by a suction pipe 25.

A control rpd 23 is adapted to move at right angles tot-he valve spindle11 between the end thereof and the end of the valve operatmg ,rod 13,and has an-inclined member 2 1 attached thereto adapted to engage, onone side the end of the spindle 11 and on the other, the'end of thevalve rod 13, so that when the inclined member 24 moves to the right itwill reduce the distance between it and the ends of the valve spindie-11 and the spill valve 0 is con- 7 valve rod 13, and so. cause avariation in the time of engagement between the said spindle and rodaccording to the extent of longitudinal movement of the governing orcontrol rod 23.

ltt will be readily understood from the above description that thefuelpump 0perates in the well known manner, so that on the down ordelivery stroke of the plungerd upon the rotation of the cam shaft 19,liquid fuel is compressed in the pipes and passages, until thepressuretherein rises to that at which the injection valve 1) isdesigned to open. After the opening of the valve 6 the continuedmovement of the cam 18 causes the valve rod 13 to open the release orspill valve 0, and on the opening of this valve the fuel pressure isreleased thereby allowing the injection valve to close automatically,and for the remainder of the fuel pump stroke the fuel is dischargedthrough the I passages 2 and 3 in the injection valve body and the pipe9 and spill valve 0 and pipe 21 to the suction pipe 25 of the fuel pump.

What I claim and desire to secure by Letters Patent is In an internalcombustion engine liquid fuel injection device, in combination, aninjection valve structure comprisin a valve chamber having an injectionoutlet and a valve controlling said outlet, said valve having a surfaceexposed to the pressure in said chamber to be opened thereby, a springresisting opening movement of said valve, 21 fuel pump connected withsaid chamber to supply fuel thereto under pressure, a spill valveconnected with said'injection valve chamber, operating means for saidpump, and means operating in synchronism with said pump operating means-for opening said spill valve during the end of each pressure stroke ofsaid pump whereby said valve chamber will be relieved of pressure andsaid injection valve allowed to close, said spill valve at other timesbeing closed.

In witness whereof I aflix'my signature.

WALTER PERCY WIDDOWSON.

